Work Environment Measure

Outline • Introduction •Work Environment Measure definition •Review of Workplace hazards •Type of Environmental Monitoring •Example of Instruments for Measurement •Applying Work Environment Measurement in Confined Space

Introduction • Industrial hygiene is the science and art devoted to the recognition, evaluation and control of environment factors and stresses arising in or from the workplace, which cause sickness, impaired health and well being, or significant discomfort and among workers or among citizens of the community. • Industrial hygiene is primarily concerned with the control of occupational health hazards that arises as a result of or during work.

Work Environment Measurement • Evaluating occupational health and safety hazards is achieved through work environment measurement, analysis of the samples and comparison of these results with established standards. • Work environment measurement refers to the determination of environment stresses and their hazardous effects on worker’s health through direct measurement of hazards using industrial hygiene equipment.

A review of Workplace Hazards Chemical Hazards Any chemical that has been classified as hazardous or for which relevant information exists to indicate that it is hazardous.

• DUST •MIST •FUMES •GAS •VAPOR

Physical Hazards Problems relating to such things as noise, vibration, temperature extremes, radiation, illumination and pressure extremes.

• NOISE •VIBRATION •TEMPERATURE EXTREMES •RADIATION •ILLUMINATION •PRESSURE EXTREMES

Cont. Workplace Hazards

Biological Hazards Any virus, bacteria, fungus, parasite, or any living organism that can cause a disease in human beings. They can be a part of the total environment or associated with certain occupations

• VIRUSES

•BATERIUM •FUNGI •PARASITES •OTHER DISEASE-CAUSING LIVING ORGANISM

Ergonomic Hazards Multidisciplinary activity dealing with interactions between man and his total working environment elements as atmosphere, heat, light and sound as well all tools and equipment in the workplace.

• IMPROPERLY DESIGNATED TOOLS OR WORK AREA •IMPROPER LIFTING •POOR VISUAL CONDITION •REPEATED MOTIONS IN AWKWARD POSITIONS

Type of Environmental Monitoring • Monitoring is a continuing program of observation, measurement and judgment, all of which are necessary to recognize potential hazards and to judge the adequacy of protection. • Monitoring requires an awareness of the presence of potential hazards and an assessment of continuing basis of the adequacy of the control measures.

Cont. Type of Environmental Monitoring

Personal / Breathing Zone Monitoring • The measurement of a particular employee’s exposure to airborne, contaminants. •In personal monitoring, the measurement device or dosimeter, is placed as possible to the contaminants’ entry portal to the body. •When monitoring an air contaminant that is toxic if inhaled, the measurement device is placed close to the breathing zone.

Area / environmental Monitoring •The measurement of the contaminant concentrations in the workroom. •The sampling device is placed in a fixed location in the work area that a generally occupied by employees. This type of collection is also referred to as environmental monitoring

Example of Instruments for Measurements 1. Illumination The measurement of the stream of light falling on a surface Lux – the unit of measurement • Luxmeter – a direct reading instrument which contains photo, light sensitive cell and micrometers which can be calibrated to read directly in lux

2. Noise Sound and noise are often used interchangeably, but generally, sound is descriptive of useful communication or pleasant sounds such as music, while noise is used to describe discord or unwanted sound. Noise may be classified as continuous, intermittent and impact. Decibel – a dimensionless unit related to the logarithm of the ratio of a measurement quantity to a reference quantity. Frequency – describes the rate at which complete cycles of high and low pressure regions produced by the sound source

Cont. NOISE

• Sound Level Meter – the instrument which measures the root-mean-square (rms) sound pressure level in decibels, which is proportional to intensity or sound energy flow. Consists of a microphone, an amplifier with calibrated volume control and an indicating meter.

Impulse Meter The special instrument which measures the peak levels of noises which lasts a fraction of a second such as those produced by hammer blows or punch press strokes

Frequency Analyzer The instrument which measures the frequency distribution of the sound energy

Sound Monitor Statistical analyzers developed to assist in indicating the percentage of time that the sound level lies in certain predetermined level ranges

3. Chemical (Common Groups)

3.1 Direct Reading Instruments 3.1.1 Single Chemical Instruments • Designed to specifically monitor for a single chemical Examples: • O2 monitors • CO2 Monitors • Etc.

3.1.2 General Survey Instruments

• Capable of detecting a large number of contaminants but generally cannot distinguish them Example: • Combustible gas indicator • Explosimeters • Photo ionization detectors • Etc.

explosimeters Combustible gas indicator

Photo ionization detectors

3.1.3 Based on Color Change • Sampling media that change color when contaminated air is pulled through them, and can provide the ability to do direct reading measurements for a wide variety of gases and vapors Examples • Detector tubes

3.2 Indirect / Integrated Air Sampling Instruments 3.2.1 Liquid Media Samplers • Devices which use an absorbing liquid to capture gaseous substances Example: • Bubblers • Impingers • Etc.

3.2.2 Solid Sorbent Sampling • A pump is used to pull air through the sorbent wherein the sampling media may be charcoal, silica gel, etc.

3.2.3 Passive Monitors • Instruments used to monitor gases and vapors and may be used relatively un attended

4.0 HEAT STRESS • The excessive heat load and is the aggregate of environmental and physical work factors that constitute the total heat load imposed on the body

• Globe, Wet and dry bulb • Thermometers

• METHANE (lighter than air) CARBON MONOXIDE (slightly lighter than air)

HYDROGEN SULFHIDE (heavier than air)

IT IS RECOMMENDED THAT IN DOING STRATIFIED AIR SAMPLING, One should apply the 2 by 2 principle*, wherein one should test for a duration of at least 2 seconds at 2 feet intervals. * This is dependent on the gas monitoring equipment used. It is best to read the user’s manual of your gas monitor prior to use

GAS MONITORING  While it is very important to detect the types and levels of gases present inside confined spaces prior to entry, it is as important that one continuously monitors gas levels in the entire duration of the confined space activity

 One must always remember that whatever activity done inside the confined space can alter the mixture of air inside.  Any or a combination of the following can happen:  Consume oxygen (and decrease oxygen level)  Displace Oxygen  Generate a combustible environment and cause an explosion (an ignition source introduced into a combustible environment)  Release toxic gases  Others

One can only ensure that he is in a “SAFE” environment if he continuously monitors his work environment. NEVER TRUST YOUR SENSES TO DETERMINE IF THE AIR INSIDE A CONFINED SPACE IS SAFE! Many gases and vapors cannot be seen or smelled. Some can be initially smelled, but can desensitize olfactory faculties at prolonged exposure. More importantly, oxygen levels cannot be determined by a person, unless one experiences its effects

TYPES OF GAS MONITORS 1.

Fixed Systems

Remote Sensors Audible/Visual Alarms Control Panels Power Supplies 

. Portable Gas Monitors

2



Single Gas Monitors

Multiple Gas Monitors

3. Points to consider when selecting Gas Monitoring  Size  Durability  Cost  Ease of use  Ease of maintenance

 Ease of calibration  Training  Intrinsic safety  Sample draw capability  RFI protection

Gas Detection with a Properly Calibrated Instrument is the ONLY SURE WAY OF KNOWING IF DANGEROUS GASES ARE PRESENT

Questions?